1561693379 has 2 divisors, whose sum is σ = 1561693380. Its totient is φ = 1561693378.

The previous prime is 1561693241. The next prime is 1561693381. The reversal of 1561693379 is 9733961651.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1561693379 - 2¹⁶ = 1561627843 is a prime.

Together with 1561693381, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1561693979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780846689 + 780846690.

It is an arithmetic number, because the mean of its divisors is an integer number (780846690).

Almost surely, 2^1561693379 is an apocalyptic number.

1561693379 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561693379 is an equidigital number, since it uses as much as digits as its factorization.

1561693379 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 918540, while the sum is 50.

The square root of 1561693379 is about 39518.2663966931. The cubic root of 1561693379 is about 1160.1974938711.

The spelling of 1561693379 in words is "one billion, five hundred sixty-one million, six hundred ninety-three thousand, three hundred seventy-nine".